Abrasion resistance

[Will]

Just read of a product recommended ( by the distributor ) for protecting boat bottoms from abrasion . This is a Kevlar reinforced epoxy paste offered by Progressive Epoxy Polymers , Pittsfield, New Hampshire .The idea is that it's sacraficial ,just reapply as it wears off .

On Mac McCarty's advise I've used West's aluminum powder applied as a thick slurry for an abrasion shield on the very bottom of a cedar strip canoe ; tough to sand smooth , but finishes to a reasonably attractive metalic grey . Seems to work . Wondered what other abrasion resisting stratagies for beach boats might be out there .

[This message has been edited by Will (edited 07-09-2001).]

[Will]

Just read of a product recommended ( by the distributor ) for protecting boat bottoms from abrasion . This is a Kevlar reinforced epoxy paste offered by Progressive Epoxy Polymers , Pittsfield, New Hampshire .The idea is that it's sacraficial ,just reapply as it wears off .

On Mac McCarty's advise I've used West's aluminum powder applied as a thick slurry for an abrasion shield on the very bottom of a cedar strip canoe ; tough to sand smooth , but finishes to a reasonably attractive metalic grey . Seems to work . Wondered what other abrasion resisting stratagies for beach boats might be out there .

[This message has been edited by Will (edited 07-09-2001).]

[Will]

Just read of a product recommended ( by the distributor ) for protecting boat bottoms from abrasion . This is a Kevlar reinforced epoxy paste offered by Progressive Epoxy Polymers , Pittsfield, New Hampshire .The idea is that it's sacraficial ,just reapply as it wears off .

On Mac McCarty's advise I've used West's aluminum powder applied as a thick slurry for an abrasion shield on the very bottom of a cedar strip canoe ; tough to sand smooth , but finishes to a reasonably attractive metalic grey . Seems to work . Wondered what other abrasion resisting stratagies for beach boats might be out there .

[This message has been edited by Will (edited 07-09-2001).]

[Tom Lathrop]

Aluminum flake powder is good. So is copper flake powder. The kind of metalic epoxy intended as a water barrier coat usually contains the flake metal variety filler. I use synthetic Xynole set in epoxy on the bottom of my boats for abrasion resistance. Polypropylene Vectra cloth is also good. Dynel cloth is not so good. Fiberglass cloth is often touted for use as an abrasion resistant sheath but is much inferior to the other two I mentioned.

[Tom Lathrop]

Aluminum flake powder is good. So is copper flake powder. The kind of metalic epoxy intended as a water barrier coat usually contains the flake metal variety filler. I use synthetic Xynole set in epoxy on the bottom of my boats for abrasion resistance. Polypropylene Vectra cloth is also good. Dynel cloth is not so good. Fiberglass cloth is often touted for use as an abrasion resistant sheath but is much inferior to the other two I mentioned.

[Tom Lathrop]

Aluminum flake powder is good. So is copper flake powder. The kind of metalic epoxy intended as a water barrier coat usually contains the flake metal variety filler. I use synthetic Xynole set in epoxy on the bottom of my boats for abrasion resistance. Polypropylene Vectra cloth is also good. Dynel cloth is not so good. Fiberglass cloth is often touted for use as an abrasion resistant sheath but is much inferior to the other two I mentioned.

[gashmore]

If it looks anything like the kevlar/epoxy I have had to sand it will be very fuzzy as it abraids.

[gashmore]

If it looks anything like the kevlar/epoxy I have had to sand it will be very fuzzy as it abraids.

[gashmore]

If it looks anything like the kevlar/epoxy I have had to sand it will be very fuzzy as it abraids.

[Will]

On sanding Kevlar : I recently had to repair a Kevlar canoe that had been run over oysters with 2 adults and a child on board .The cloth was showing , includeing some hairy filiments that I knew I couldn't sand .I sized the damaged area with thin epoxy ( on hand for working with the afore mentioned canoe )and after it was set I scraped all smooth with a scaper blade . I was caught short in a remote area and had to hone the back of a handsaw for a scraper which I found works perfectly and produces a usefull large flexible one for boatwork .

[Will]

On sanding Kevlar : I recently had to repair a Kevlar canoe that had been run over oysters with 2 adults and a child on board .The cloth was showing , includeing some hairy filiments that I knew I couldn't sand .I sized the damaged area with thin epoxy ( on hand for working with the afore mentioned canoe )and after it was set I scraped all smooth with a scaper blade . I was caught short in a remote area and had to hone the back of a handsaw for a scraper which I found works perfectly and produces a usefull large flexible one for boatwork .

[Will]

On sanding Kevlar : I recently had to repair a Kevlar canoe that had been run over oysters with 2 adults and a child on board .The cloth was showing , includeing some hairy filiments that I knew I couldn't sand .I sized the damaged area with thin epoxy ( on hand for working with the afore mentioned canoe )and after it was set I scraped all smooth with a scaper blade . I was caught short in a remote area and had to hone the back of a handsaw for a scraper which I found works perfectly and produces a usefull large flexible one for boatwork .

[Tom Dugan]

Now here's a topic I've been curious about for some time.

Most of the Wee Lassie class of canoes I've studied (anything 13' and under & ultralight)call for some cloth -usually fiberglass - set in epoxy. But I'm afraid (i.e. no data to back this up) that this adds unneccesary weight to the boat. Am I right?

I guess my question boils down to: What's the best abrasion resistance for the weight added? Or maybe: What's the lightest-weight effective abrasion resistance you've used?

-T

Pee Ess: I recognize the strength/stiffness characteristics that epoxy-soaked cloth add, but that's not what this thread's about, is it http://media5.hypernet.com/~dick/ubb/smile.gif

[Tom Dugan]

Now here's a topic I've been curious about for some time.

Most of the Wee Lassie class of canoes I've studied (anything 13' and under & ultralight)call for some cloth -usually fiberglass - set in epoxy. But I'm afraid (i.e. no data to back this up) that this adds unneccesary weight to the boat. Am I right?

I guess my question boils down to: What's the best abrasion resistance for the weight added? Or maybe: What's the lightest-weight effective abrasion resistance you've used?

-T

Pee Ess: I recognize the strength/stiffness characteristics that epoxy-soaked cloth add, but that's not what this thread's about, is it http://media5.hypernet.com/~dick/ubb/smile.gif

[Tom Dugan]

Now here's a topic I've been curious about for some time.

Most of the Wee Lassie class of canoes I've studied (anything 13' and under & ultralight)call for some cloth -usually fiberglass - set in epoxy. But I'm afraid (i.e. no data to back this up) that this adds unneccesary weight to the boat. Am I right?

I guess my question boils down to: What's the best abrasion resistance for the weight added? Or maybe: What's the lightest-weight effective abrasion resistance you've used?

-T

Pee Ess: I recognize the strength/stiffness characteristics that epoxy-soaked cloth add, but that's not what this thread's about, is it http://media5.hypernet.com/~dick/ubb/smile.gif

[Tom Lathrop]

I ran some abrasion tests on several materials set in epoxy a couple years ago. Tests were done in a fairly scientific manner on a home made automatic rig that timed penetration with an electric clock. Synthetic cloths were all superior to fiberglass.

Some results of time to penetrate the sheath follow. The resultant times were normalized to equal thickness since thickness of the sheath varied with each type. Using plain epoxy as the baseline, the relative time to penetrate equal thickness sheaths are:

epoxy only 1
fiberglass 1.6
Vectra polypropylene 2.2
Dynel 2.6
Xynole 3.7

Be aware that more epoxy is needed to cover the synthetics to a nice finish than on the smoother fiberglass, so more weight will be gained, even though the cloth material alone may be lighter. In some cases this is a disadvantage, and sometimes not when extra waterproofing is wanted.

I will check to see if I have enough data to get the relative weight of the different sheaths.

[This message has been edited by Tom Lathrop (edited 07-10-2001).]

[Tom Lathrop]

I ran some abrasion tests on several materials set in epoxy a couple years ago. Tests were done in a fairly scientific manner on a home made automatic rig that timed penetration with an electric clock. Synthetic cloths were all superior to fiberglass.

Some results of time to penetrate the sheath follow. The resultant times were normalized to equal thickness since thickness of the sheath varied with each type. Using plain epoxy as the baseline, the relative time to penetrate equal thickness sheaths are:

epoxy only 1
fiberglass 1.6
Vectra polypropylene 2.2
Dynel 2.6
Xynole 3.7

Be aware that more epoxy is needed to cover the synthetics to a nice finish than on the smoother fiberglass, so more weight will be gained, even though the cloth material alone may be lighter. In some cases this is a disadvantage, and sometimes not when extra waterproofing is wanted.

I will check to see if I have enough data to get the relative weight of the different sheaths.

[This message has been edited by Tom Lathrop (edited 07-10-2001).]

[Tom Lathrop]

I ran some abrasion tests on several materials set in epoxy a couple years ago. Tests were done in a fairly scientific manner on a home made automatic rig that timed penetration with an electric clock. Synthetic cloths were all superior to fiberglass.

Some results of time to penetrate the sheath follow. The resultant times were normalized to equal thickness since thickness of the sheath varied with each type. Using plain epoxy as the baseline, the relative time to penetrate equal thickness sheaths are:

epoxy only 1
fiberglass 1.6
Vectra polypropylene 2.2
Dynel 2.6
Xynole 3.7

Be aware that more epoxy is needed to cover the synthetics to a nice finish than on the smoother fiberglass, so more weight will be gained, even though the cloth material alone may be lighter. In some cases this is a disadvantage, and sometimes not when extra waterproofing is wanted.

I will check to see if I have enough data to get the relative weight of the different sheaths.

[This message has been edited by Tom Lathrop (edited 07-10-2001).]

[Todd Bradshaw]

On small canoes the sheathing may be doing double-duty, so separating one fabric out for abrasion resistance alone may leave you short somewhere else in the structure. Glass provides more stiffness than most of the others and may be a lot of what's keeping the hull in shape. It's also available in a lot more weights and weaves than the other fabrics and may actually be the best solution in terms of weight added, stiffness and adding at least some abrasion resistance.

Other than those occasional unseen rock encounters, abrasion on a canoe is fairly predictable. High wear areas can often be protected separately with selective placements of small amounts of material. I generally use strips of Kevlar felt about 1/2" wide, set in epoxy with peel-ply over it to help keep it smooth (you can't sand it) on high wear areas like stems below the waterline. The stuff just does not abrade. On the other hand, a brass stem band ain't bad either.

[Todd Bradshaw]

On small canoes the sheathing may be doing double-duty, so separating one fabric out for abrasion resistance alone may leave you short somewhere else in the structure. Glass provides more stiffness than most of the others and may be a lot of what's keeping the hull in shape. It's also available in a lot more weights and weaves than the other fabrics and may actually be the best solution in terms of weight added, stiffness and adding at least some abrasion resistance.

Other than those occasional unseen rock encounters, abrasion on a canoe is fairly predictable. High wear areas can often be protected separately with selective placements of small amounts of material. I generally use strips of Kevlar felt about 1/2" wide, set in epoxy with peel-ply over it to help keep it smooth (you can't sand it) on high wear areas like stems below the waterline. The stuff just does not abrade. On the other hand, a brass stem band ain't bad either.

[Todd Bradshaw]

On small canoes the sheathing may be doing double-duty, so separating one fabric out for abrasion resistance alone may leave you short somewhere else in the structure. Glass provides more stiffness than most of the others and may be a lot of what's keeping the hull in shape. It's also available in a lot more weights and weaves than the other fabrics and may actually be the best solution in terms of weight added, stiffness and adding at least some abrasion resistance.

Other than those occasional unseen rock encounters, abrasion on a canoe is fairly predictable. High wear areas can often be protected separately with selective placements of small amounts of material. I generally use strips of Kevlar felt about 1/2" wide, set in epoxy with peel-ply over it to help keep it smooth (you can't sand it) on high wear areas like stems below the waterline. The stuff just does not abrade. On the other hand, a brass stem band ain't bad either.

[Tom Lathrop]

OK, I looked at the data and made some informed educated guesses at the relative weights of the different sheaths. I used only the total sheath thickness as a guide since the weight difference contributed by the fabrics is too small for me to measure.

Again normalizing to the fiberglass, the relative weights are:

fiberglass ------- 1
Vectra ----------- 1.7
Dynel ------------ 2.4
Xynole ----------- 2.9

The synthetics all weigh less than the glass per sq yd. Vectra polypropylene comes out lighter than the other synthetics because it has a smooth finish very much like fiberglass and the filaments do not absorb epoxy while the Dynel and, especially, the Xynole have a more coarse finish and do take up a lot of epoxy.

Don't know if this helps your decision making or not, but it's what I have found. Anyway, glass seems to be a poor choice for abrasion resistance.

What Todd says is also in the equation, so you just have to decide what characteristics are most important in a particular situation.

[This message has been edited by Tom Lathrop (edited 07-10-2001).]

[Tom Lathrop]

OK, I looked at the data and made some informed educated guesses at the relative weights of the different sheaths. I used only the total sheath thickness as a guide since the weight difference contributed by the fabrics is too small for me to measure.

Again normalizing to the fiberglass, the relative weights are:

fiberglass ------- 1
Vectra ----------- 1.7
Dynel ------------ 2.4
Xynole ----------- 2.9

The synthetics all weigh less than the glass per sq yd. Vectra polypropylene comes out lighter than the other synthetics because it has a smooth finish very much like fiberglass and the filaments do not absorb epoxy while the Dynel and, especially, the Xynole have a more coarse finish and do take up a lot of epoxy.

Don't know if this helps your decision making or not, but it's what I have found. Anyway, glass seems to be a poor choice for abrasion resistance.

What Todd says is also in the equation, so you just have to decide what characteristics are most important in a particular situation.

[This message has been edited by Tom Lathrop (edited 07-10-2001).]

[Tom Lathrop]

OK, I looked at the data and made some informed educated guesses at the relative weights of the different sheaths. I used only the total sheath thickness as a guide since the weight difference contributed by the fabrics is too small for me to measure.

Again normalizing to the fiberglass, the relative weights are:

fiberglass ------- 1
Vectra ----------- 1.7
Dynel ------------ 2.4
Xynole ----------- 2.9

The synthetics all weigh less than the glass per sq yd. Vectra polypropylene comes out lighter than the other synthetics because it has a smooth finish very much like fiberglass and the filaments do not absorb epoxy while the Dynel and, especially, the Xynole have a more coarse finish and do take up a lot of epoxy.

Don't know if this helps your decision making or not, but it's what I have found. Anyway, glass seems to be a poor choice for abrasion resistance.

What Todd says is also in the equation, so you just have to decide what characteristics are most important in a particular situation.

[This message has been edited by Tom Lathrop (edited 07-10-2001).]

[Will]

I think Todds kevlar felt may fit my current case ; adding a wear strip to the stem and stern of an abraided double ended sailboat . I found a source for kevlar tape on the web , but feared I'd never get it to lay flat .Hadn't heard of the felt , where do you get it ? Sounds like it might be easier to apply smoothly than the paste .

[Will]

I think Todds kevlar felt may fit my current case ; adding a wear strip to the stem and stern of an abraided double ended sailboat . I found a source for kevlar tape on the web , but feared I'd never get it to lay flat .Hadn't heard of the felt , where do you get it ? Sounds like it might be easier to apply smoothly than the paste .

[Will]

I think Todds kevlar felt may fit my current case ; adding a wear strip to the stem and stern of an abraided double ended sailboat . I found a source for kevlar tape on the web , but feared I'd never get it to lay flat .Hadn't heard of the felt , where do you get it ? Sounds like it might be easier to apply smoothly than the paste .

[Todd Bradshaw]

About the only handy source for Kevlar felt would be a whitewater canoe dealer. Companies like Old Town and Mad River sell "Kevlar Skid Plate Kits" to reinforce the stems of Royalex canoes. You get a couple pre-cut hunks of felt maybe 5" wide by 25" long and a can of resin. The resin is epoxy, but it's a flexible formulation designed to stick to the vinyl skin of Royalex boats. On a wooden boat, I think you're better off using one of the epoxies made for wooden boat building (WEST, System-3 etc.) The resin's flex has nothing to do with the durability of the Kevlar and I find regular resins more predictable.

The kits aren't cheap, but from one kit you can get enough felt to do a lot of small reinforcements. You probably also want to plan to paint over the felt - both to protect the resin from U.V. and because while unbelievably durable, the stuff isn't very pretty to look at.

A friend of mine was a big-wig at Old Town around the time they developed the skid plates. He said they installed them on a test canoe, hung it out the back of a pickup, put some rocks inside and drove the boat around town one afternoon with the Kevlar protected stem dragging on the pavement and never wore through the skid plate. I always wanted to get a big chunk of it and sew-up a bullet-proof chamois shirt...it never hurts to be prepared....

[Todd Bradshaw]

About the only handy source for Kevlar felt would be a whitewater canoe dealer. Companies like Old Town and Mad River sell "Kevlar Skid Plate Kits" to reinforce the stems of Royalex canoes. You get a couple pre-cut hunks of felt maybe 5" wide by 25" long and a can of resin. The resin is epoxy, but it's a flexible formulation designed to stick to the vinyl skin of Royalex boats. On a wooden boat, I think you're better off using one of the epoxies made for wooden boat building (WEST, System-3 etc.) The resin's flex has nothing to do with the durability of the Kevlar and I find regular resins more predictable.

The kits aren't cheap, but from one kit you can get enough felt to do a lot of small reinforcements. You probably also want to plan to paint over the felt - both to protect the resin from U.V. and because while unbelievably durable, the stuff isn't very pretty to look at.

A friend of mine was a big-wig at Old Town around the time they developed the skid plates. He said they installed them on a test canoe, hung it out the back of a pickup, put some rocks inside and drove the boat around town one afternoon with the Kevlar protected stem dragging on the pavement and never wore through the skid plate. I always wanted to get a big chunk of it and sew-up a bullet-proof chamois shirt...it never hurts to be prepared....

[Todd Bradshaw]

About the only handy source for Kevlar felt would be a whitewater canoe dealer. Companies like Old Town and Mad River sell "Kevlar Skid Plate Kits" to reinforce the stems of Royalex canoes. You get a couple pre-cut hunks of felt maybe 5" wide by 25" long and a can of resin. The resin is epoxy, but it's a flexible formulation designed to stick to the vinyl skin of Royalex boats. On a wooden boat, I think you're better off using one of the epoxies made for wooden boat building (WEST, System-3 etc.) The resin's flex has nothing to do with the durability of the Kevlar and I find regular resins more predictable.

The kits aren't cheap, but from one kit you can get enough felt to do a lot of small reinforcements. You probably also want to plan to paint over the felt - both to protect the resin from U.V. and because while unbelievably durable, the stuff isn't very pretty to look at.

A friend of mine was a big-wig at Old Town around the time they developed the skid plates. He said they installed them on a test canoe, hung it out the back of a pickup, put some rocks inside and drove the boat around town one afternoon with the Kevlar protected stem dragging on the pavement and never wore through the skid plate. I always wanted to get a big chunk of it and sew-up a bullet-proof chamois shirt...it never hurts to be prepared....

[Will]

Todd ; I'm a whitewater canoeist myself so I know about the Grung Pads as we call them .Effective , but a bit uncouth . Whitewater is an extremity of small boating and demands extreme measures . They're not just for abrasion , I've seen them ( from close up ) take huge impacts .

Thanks for the data Tom . I think examining the Lathrop Ratio ( durability/wieght ) of each material could guide the selection of cloth for this purpose.

Dynel 1.1
Vectra 1.3
Xynol 1.3
Fiberglass 1.6

Among this group it looks like useing fiberglass is the way to go when applying sacraficial abrasion protection on even the lightest boats. Would you be willing to test a thick aluminum-epoxy mix the same way , and some kevlar cloth ?




[This message has been edited by Will (edited 07-11-2001).]

[Will]

Todd ; I'm a whitewater canoeist myself so I know about the Grung Pads as we call them .Effective , but a bit uncouth . Whitewater is an extremity of small boating and demands extreme measures . They're not just for abrasion , I've seen them ( from close up ) take huge impacts .

Thanks for the data Tom . I think examining the Lathrop Ratio ( durability/wieght ) of each material could guide the selection of cloth for this purpose.

Dynel 1.1
Vectra 1.3
Xynol 1.3
Fiberglass 1.6

Among this group it looks like useing fiberglass is the way to go when applying sacraficial abrasion protection on even the lightest boats. Would you be willing to test a thick aluminum-epoxy mix the same way , and some kevlar cloth ?




[This message has been edited by Will (edited 07-11-2001).]

[Will]

Todd ; I'm a whitewater canoeist myself so I know about the Grung Pads as we call them .Effective , but a bit uncouth . Whitewater is an extremity of small boating and demands extreme measures . They're not just for abrasion , I've seen them ( from close up ) take huge impacts .

Thanks for the data Tom . I think examining the Lathrop Ratio ( durability/wieght ) of each material could guide the selection of cloth for this purpose.

Dynel 1.1
Vectra 1.3
Xynol 1.3
Fiberglass 1.6

Among this group it looks like useing fiberglass is the way to go when applying sacraficial abrasion protection on even the lightest boats. Would you be willing to test a thick aluminum-epoxy mix the same way , and some kevlar cloth ?




[This message has been edited by Will (edited 07-11-2001).]

[Tom Dugan]

Well first I have to say thanks to Tom and Todd, and Will, for the responses to my question.

There is, of course, another factor at work here - the Beautious Factor. I too am familiar with the whitewater world, where there's sort of an Inverse Beautious Factor at work. In the Form Follows Function vein, they let the (generally ugly) utilitarian items stand proud.

But when we're talking about a lapstrake or stripped wooden canoe, chances are that any wear protection is going to be covered up as best as possible. (I know mine are, anyway.)
I'd want something smooth and painted so it blends with the rest of the hull. If I wanted to try something other than the fiberglass cloth, I'd probably settle for a thicker coating (xynole), and maybe make up some weight by thinning down the bottom planks - although I already use 3mm ply and can't imagine going thinner.

I guess this is what puzzles me about Will's reference to the aluminum powder. It sounds like it produces a rough finish, and I imagine it doesn't get a paint job. OTOH, it's probably better at abrasion resistance than straight epoxy and lighter than an epoxy/fiberglass coat. Is that the gist?

Maybe I oughta try the kevlar paste, just fer grins.

So many choices, so little time.

-T

[Tom Dugan]

Well first I have to say thanks to Tom and Todd, and Will, for the responses to my question.

There is, of course, another factor at work here - the Beautious Factor. I too am familiar with the whitewater world, where there's sort of an Inverse Beautious Factor at work. In the Form Follows Function vein, they let the (generally ugly) utilitarian items stand proud.

But when we're talking about a lapstrake or stripped wooden canoe, chances are that any wear protection is going to be covered up as best as possible. (I know mine are, anyway.)
I'd want something smooth and painted so it blends with the rest of the hull. If I wanted to try something other than the fiberglass cloth, I'd probably settle for a thicker coating (xynole), and maybe make up some weight by thinning down the bottom planks - although I already use 3mm ply and can't imagine going thinner.

I guess this is what puzzles me about Will's reference to the aluminum powder. It sounds like it produces a rough finish, and I imagine it doesn't get a paint job. OTOH, it's probably better at abrasion resistance than straight epoxy and lighter than an epoxy/fiberglass coat. Is that the gist?

Maybe I oughta try the kevlar paste, just fer grins.

So many choices, so little time.

-T

[Tom Dugan]

Well first I have to say thanks to Tom and Todd, and Will, for the responses to my question.

There is, of course, another factor at work here - the Beautious Factor. I too am familiar with the whitewater world, where there's sort of an Inverse Beautious Factor at work. In the Form Follows Function vein, they let the (generally ugly) utilitarian items stand proud.

But when we're talking about a lapstrake or stripped wooden canoe, chances are that any wear protection is going to be covered up as best as possible. (I know mine are, anyway.)
I'd want something smooth and painted so it blends with the rest of the hull. If I wanted to try something other than the fiberglass cloth, I'd probably settle for a thicker coating (xynole), and maybe make up some weight by thinning down the bottom planks - although I already use 3mm ply and can't imagine going thinner.

I guess this is what puzzles me about Will's reference to the aluminum powder. It sounds like it produces a rough finish, and I imagine it doesn't get a paint job. OTOH, it's probably better at abrasion resistance than straight epoxy and lighter than an epoxy/fiberglass coat. Is that the gist?

Maybe I oughta try the kevlar paste, just fer grins.

So many choices, so little time.

-T

[Tom Dugan]

I should probably add that I never figured I'd have much of an abrasion problem, living and canoeing in Tidewater Maryland (i.e. no rocks). But last week I managed to smack rocks a couple of times pretty good. And that was in the C&O Canal! So ya just never know....

-T

[Tom Dugan]

I should probably add that I never figured I'd have much of an abrasion problem, living and canoeing in Tidewater Maryland (i.e. no rocks). But last week I managed to smack rocks a couple of times pretty good. And that was in the C&O Canal! So ya just never know....

-T

[Tom Dugan]

I should probably add that I never figured I'd have much of an abrasion problem, living and canoeing in Tidewater Maryland (i.e. no rocks). But last week I managed to smack rocks a couple of times pretty good. And that was in the C&O Canal! So ya just never know....

-T

[Will]

Tom , the aluminum stuff sands perfectly smooth and can be painted ,I just ment it was Hard to sand . We can't tell if it's lighter than the cloths discussed for a given level of resistance unless Tom L will do his scratch test on some .



[This message has been edited by Will (edited 07-11-2001).]

[Will]

Tom , the aluminum stuff sands perfectly smooth and can be painted ,I just ment it was Hard to sand . We can't tell if it's lighter than the cloths discussed for a given level of resistance unless Tom L will do his scratch test on some .



[This message has been edited by Will (edited 07-11-2001).]

[Will]

Tom , the aluminum stuff sands perfectly smooth and can be painted ,I just ment it was Hard to sand . We can't tell if it's lighter than the cloths discussed for a given level of resistance unless Tom L will do his scratch test on some .



[This message has been edited by Will (edited 07-11-2001).]

[Tom Lathrop]

Will,

I think that something was lost in the translation of the data. The relative abrasion resistance table that I gave already accounted for the weight and thickness factors. Therefore, the Xynole is actually 3.7 times as resistant as the epoxy alone for EQUAL thickness and weight and 2.3 times as resistant as fiberglass for equal thickness and weight.

The actual times to penetrate a sheath of 9oz fiberglass (.018 in thick) and a sheath of Xynole (.053 in thick) were 65 seconds for glass and 436 seconds for Xynole. Therefore for the extra weight of the Xynole sheath, you get a sheath that is 436 divided by 65, or 6.7 times the abrasion resistance of the glass. When actually trying to sand the stuff, it seems like even more than that. If you used 6oz or 4oz glass cloth, it would be lighter, but the ratio would be higher yet.

I am not anti glass. In fact I use it a lot, just not for abrasion resistance. If you are using a thick glass sheath for strength, like one or more layers of bias ply knytex, then there will be a lot of abrasion resistance in that.

If you send me the aluminum paste and Kevlar materials, I will be glad to run the tests on them. I have some aluminum powder that I got from WEST quite a few years ago and can run that but it may not be the same. I also have some copperpoxy paste and can run that too.

The latest copy of Boatbuilder magazine just came in the mail and there is a letter from the supplier of the Kevlar paste there.

Tom

[Tom Lathrop]

Will,

I think that something was lost in the translation of the data. The relative abrasion resistance table that I gave already accounted for the weight and thickness factors. Therefore, the Xynole is actually 3.7 times as resistant as the epoxy alone for EQUAL thickness and weight and 2.3 times as resistant as fiberglass for equal thickness and weight.

The actual times to penetrate a sheath of 9oz fiberglass (.018 in thick) and a sheath of Xynole (.053 in thick) were 65 seconds for glass and 436 seconds for Xynole. Therefore for the extra weight of the Xynole sheath, you get a sheath that is 436 divided by 65, or 6.7 times the abrasion resistance of the glass. When actually trying to sand the stuff, it seems like even more than that. If you used 6oz or 4oz glass cloth, it would be lighter, but the ratio would be higher yet.

I am not anti glass. In fact I use it a lot, just not for abrasion resistance. If you are using a thick glass sheath for strength, like one or more layers of bias ply knytex, then there will be a lot of abrasion resistance in that.

If you send me the aluminum paste and Kevlar materials, I will be glad to run the tests on them. I have some aluminum powder that I got from WEST quite a few years ago and can run that but it may not be the same. I also have some copperpoxy paste and can run that too.

The latest copy of Boatbuilder magazine just came in the mail and there is a letter from the supplier of the Kevlar paste there.

Tom

[Tom Lathrop]

Will,

I think that something was lost in the translation of the data. The relative abrasion resistance table that I gave already accounted for the weight and thickness factors. Therefore, the Xynole is actually 3.7 times as resistant as the epoxy alone for EQUAL thickness and weight and 2.3 times as resistant as fiberglass for equal thickness and weight.

The actual times to penetrate a sheath of 9oz fiberglass (.018 in thick) and a sheath of Xynole (.053 in thick) were 65 seconds for glass and 436 seconds for Xynole. Therefore for the extra weight of the Xynole sheath, you get a sheath that is 436 divided by 65, or 6.7 times the abrasion resistance of the glass. When actually trying to sand the stuff, it seems like even more than that. If you used 6oz or 4oz glass cloth, it would be lighter, but the ratio would be higher yet.

I am not anti glass. In fact I use it a lot, just not for abrasion resistance. If you are using a thick glass sheath for strength, like one or more layers of bias ply knytex, then there will be a lot of abrasion resistance in that.

If you send me the aluminum paste and Kevlar materials, I will be glad to run the tests on them. I have some aluminum powder that I got from WEST quite a few years ago and can run that but it may not be the same. I also have some copperpoxy paste and can run that too.

The latest copy of Boatbuilder magazine just came in the mail and there is a letter from the supplier of the Kevlar paste there.

Tom

[Will]

Oh,O.K. I'm also useing Wests aluminum powder .It would be interesting to hear how it compares with the cloths .

[Will]

Oh,O.K. I'm also useing Wests aluminum powder .It would be interesting to hear how it compares with the cloths .

[Will]

Oh,O.K. I'm also useing Wests aluminum powder .It would be interesting to hear how it compares with the cloths .